1. Field of the Invention
The present invention relates generally to structures for bridges, roadway overpasses, and the like, and more specifically to a prefabricated pier system in which both the pier bases and pier caps are prefabricated at a manufacturing facility removed from the construction site, and shipped to the construction site for assembly. The pier caps then serve as permanent forms for the casting of the concrete pier cap beams for the structure.
2. Description of Related Art
Conventionally, bridge and overpass construction involves the on site construction of a series of temporary forms for casting reinforced concrete structural members, which forms are later removed once the concrete has cured. This is generally a relatively long and drawn out process, as it is necessary initially to construct forms for the pier foundations, then wait for the concrete to cure before forming further concrete structures above the foundations, with a further delay for curing before finally forming the pier caps and upper structure.
The time required for concrete to cure to full strength can take days or even weeks, depending upon the concrete mass, the mixture used, the curing process, the weather and temperature, and perhaps other factors as well. Yet, with conventional construction where a series of concrete components are formed progressively from the footings, some delay at each step of the way is required due to the time required for constructing concrete forms for each step and the curing time for each of the several concrete castings required. As a result, conventional bridge construction is a time intensive operation, even where many prefabricated components (prestressed concrete beams and slabs, steel girders, etc.) are used. The relatively large amount of time required also greatly increases the costs of such projects, due to the necessity of keeping the required labor force on the payroll through completion of the project or at least until that labor is no longer required. Obviously, some means of reducing much of the delay in such conventional construction is a desirable goal.
Accordingly, the present invention provides a solution to the above problem by providing a prefabricated pier system which eliminates most of the above steps in the construction of a bridge or the like. The present invention comprises the fabrication of a series of pier bases and pier caps at a manufacturing site remote from the bridge construction site, with the prefabricated components then being shipped to the construction site for installation.
The prefabricated pier bases are then set into a concrete footing at the construction site, with a corresponding series of steel pier members then installed and welded in the pier bases after the concrete footing has cured. The prefabricated pier caps are then installed and welded to the tops of the piers, with the caps serving as permanently installed forms for casting the transverse pier cap beams in place. The present construction thus greatly reduces the number of pours of concrete used in conventional bridge construction, and accordingly greatly reduces the time required and corresponding labor and other costs incurred in such construction.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions in comparison to the present invention, is provided below.
U.S. Pat. No. 3,100,968 issued on Aug. 20, 1963 to Thomas E. Bourdon, titled xe2x80x9cMarine Dock,xe2x80x9d describes a dock structure adapted to temporary, seasonal installation in a body of water. The pier foundations comprise a series of heavy metal bases with two metal columns extending upwardly from each base, with no direct connection between the bases. A transverse beam is installed between each set of columns of each pair of bases. However, the transverse beam is a continuous structure, with no prefabricated pier caps being disclosed for the fabrication of the transverse beam on site. The Bourdon structure teaches away from the present permanently installed bridge construction, as the Bourdon structure must be relatively light for portability.
U.S. Pat. No. 3,662,559 issued on May 16, 1972 to Wesley K. Swift, titled xe2x80x9cAnchorage For Boat Docks,xe2x80x9d describes a floating dock structure with permanently installed piers. The pier structure comprises a pair of vertical columns linked together for stability, with concrete poured around the bases and link for security. Sleeves are attached to the dock structure to ride vertically along the pier columns, with the buoyant dock structure floating on the surface of the water as is well known in the art. Swift teaches away from the present invention with his buoyant dock structure movably secured to his vertical piers. He does not disclose any form of permanently installed pier caps immovably affixed to the vertical piers, nor the use of concrete for any of the upper structure of his pier, as is done with the present prefabricated pier structure.
U.S. Pat. No. 3,798,867 issued on Mar. 26, 1974 to Benjamin F. Starling, titled xe2x80x9cStructural Method And Apparatus,xe2x80x9d describes a method of repairing existing, previously installed support columns and piers, rather than the fabrication of new structures as provided by the present invention. Starling provides a casing or enclosure which is installed around the existing column, with a suitable agent (epoxy or concrete) being poured into the casing to surround and reinforce the existing column. While Starling discloses such a reinforcement method in combination with an HP (H section pier) member, he does not disclose any means of installing the HP member in the first place, nor any means of providing a prefabricated pier cap for forming the pier cap beam.
U.S. Pat. No. 3,894,374 issued on Jul. 15, 1975 to Pierre Faucheaux, titled xe2x80x9cSet Of Elements For The Construction Of Buildings,xe2x80x9d describes provision of a base plate which is imbedded in concrete to form a foundation structure. The base plate includes upright tubular members upon which vertical support posts are installed. A series of transverse beams are then installed atop the vertical posts. The posts and beams are hollow, and comprise non-recoverable forms for pouring concrete therein. However, the Faucheaux construction does not provide a series of prefabricated pier caps which are joined together to provide a pier beam form, as provided by the present prefabricated pier system.
U.S. Pat. No. 4,349,297 issued on Sep. 14, 1982 to Terrance J. Misener, titled xe2x80x9cBoat Dock,xe2x80x9d describes a dock structure having a series of separate pier foundations, with each foundation having a single tubular pier extending vertically upwardly therefrom. The piers are joined longitudinally by tubular stringers essentially defining the two edges of the dock, with a series of transverse plastic planks installed over the stringers. This construction does not require the transverse pier beams of the present bridge construction, and accordingly does not provide any prefabricated pier caps, as provided in the present pier construction. Moreover, the pier foundations of the Misener dock construction are not directly connected to one another, whereas the piers of each pier assembly of the present construction are all directly connected at their upper and lower ends, respectively by the corresponding pier foundation and pier cap beam.
U.S. Pat. No. 4,409,764 issued on Oct. 18, 1983 to John A. Wilnau, titled xe2x80x9cSystem And Method For Reinforced Concrete Construction,xe2x80x9d describes a system having a series of prefabricated hollow forms which are bolted in place and to one another, with a single pouring of concrete being made to fill all of the internally interconnected forms. Wilnau does not provide a single pier foundation structure which is set into a single corresponding footing dug therefor, as in the present pier system. Rather, each column of the Wilnau construction has its own, separate foundation. Moreover, Wilnau utilizes a pair of widely spaced reinforced concrete columns to support a lateral beam of reinforced concrete thereacross, unlike the series of steel HP members which support the bolted together pier cap sections, and thus the reinforced concrete pier cap beam formed therein, of the present system.
U.S. Pat. No. 4,550,536 issued on Nov. 5, 1985 to Jean F. Lamoure, titled xe2x80x9cIndustrial Building Framework Formed From Prefabricated Reenforced Concrete Elements,xe2x80x9d describes a building framework constructed of a series of precast or prestressed concrete members. Lamoure teaches away from the present pier construction, in that he states that his concrete members are all prefabricated (column 1, line 11). Thus, he has no motivation to provide pier caps or the like constructed of a series of separate shells or forms which may be joined together at the construction site for forming a concrete pier cap beam on-site, as the present invention provides.
U.S. Pat. No. 4,767,241 issued on Aug. 30, 1988 to Gordon T. Wells, titled xe2x80x9cMethod For Simultaneous Forming Of Concrete Footings And Piers,xe2x80x9d describes a pier system having a hollow foundation and tubular pier column, with the hollow interiors of the foundation and pier column communicating with one another. Concrete is poured into the assembly to provide simultaneous fill of both the foundation and the pier. The Wells system teaches away from the present system, in that the present system utilizes HP (H section pier) members rather than hollow pier supports. Moreover, Wells is silent regarding any form of pier cap structure for his pier and footing forming method, whereas one of the key aspects of the present invention is the prefabricated construction of the pier cap sections at a location removed from the construction site, and their assembly at the construction site to form the pier cap beams.
U.S. Pat. No. 4,977,636 issued on Dec. 18, 1990 to John B. King, titled xe2x80x9cPile Supported Bridge Assembly,xe2x80x9d describes a system using precast concrete members for the pilings or piers, the pier cap beams, and the slabs used to form the foundation for the road surface thereover. King recognizes the problem of excessive environmental damage which may occur when concrete structures are formed on site, as well as the time required for on site concrete construction methods. However, King is silent regarding the installation of any footings for the piers, and moreover teaches away from the present invention by precasting his concrete pier beams off site, rather than prefabricating pier caps and assembling them on site to serve as pier beam forms, as in the present system.
U.S. Pat. No. 5,210,991 issued on May 18, 1993 to Jaakko Hakala et al., titled xe2x80x9cMethod For Making The Foundation Slabs Of A Paper Machine Before The Installation Proper Of The Machine,xe2x80x9d describes the steps involved in the construction of a foundation for a paper making machine. Hakala et al. form the horizontal support beams in situ atop vertical pilings, somewhat in the manner used for the present pier construction. However, Hakala et al. do not provide a multiple segment, prefabricated form or mold for the beam, as is the case with the present construction system. Moreover, Hakala et al. bolt the beam to the underlying piers, rather than welding the steel form or mold to the piers, as is the case with the present construction system. Also, Hakala et al. are silent regarding any form of footing structure for their piers.
U.S. Pat. No. 5,771,518 issued on Jun. 30, 1998 to Michael L. Roberts, titled xe2x80x9cPrecast Concrete Bridge Structure And Associated Rapid Assembly Methods,xe2x80x9d describes a system wherein all major components are formed of concrete. The piers are formed of a quick setting polymer concrete, which is pumped downwardly through the aggregate material with which the outer shells of the piers have been filled. The Roberts deck support beams also appear to be formed of precast reinforced concrete, rather than being formed of rolled steel, as in the case of the deck support beams and piers of the present system. Moreover, Roberts does not disclose any form of prefabricated, multiple unit modular pier cap beam forms for assembly in situ for forming the pier cap beams, as provided by the present construction system.
U.S. Pat. No. 5,836,124 issued on Nov. 17, 1998 to Nils Aspehaug et al., titled xe2x80x9cFoundation Tube For Use As A Foundation For Masts, Posts, Pillars, Etc.,xe2x80x9d describes a method of installing a tubular member into the underlying substrate. A footing hole is dug and the tube is inserted therein, with concrete being pumped downwardly around the outer circumference of the tube, between the tube and the ground. The tube may have perforations to allow the concrete to flow into the center of the lower end of the tube. The present invention differs considerably in using structural steel pier members which are inserted into steel sockets which are in turn welded to a steel foundation structure which is set into a concrete foundation. Aspehaug et al. are silent regarding any form of structure which resides atop and/or is supported by their pier structure.
U.S. Pat. No. 5,870,789 issued on Feb. 16, 1999 to Rene Carranza-Aubry, titled xe2x80x9cPrecast Bridges,xe2x80x9d describes another bridge structure in which all of the major components are formed of precast, reinforced concrete. The Carranza-Aubry structure includes various interlocking shapes to provide a secure structure. However, Carranza-Aubry does not disclose the use of steel foundation sockets for supporting steel HP members, as provided by the present invention, nor does he disclose the prefabrication of a plurality of modular pier beam cap forms for assembly at the construction site for use in forming the reinforced concrete pier caps on site, as provided by the present construction system.
U.S. Pat. No. 5,946,867 issued on Sep. 7, 1999 to Randle P. Snider, Jr. et al., titled xe2x80x9cModular Earthquake Support For Raised Floor,xe2x80x9d describes a structure formed of a series of steel beams and columns, with the columns being bolted into sockets which are mounted to plates bolted to the underlying concrete floor. While the Snider, Jr. et al. structure could be extended to form a longer structure, such as a bridge, Snider, Jr. et al. do not use any concrete in their structure, other than the conventional concrete slab used for the floor of the surrounding building structure in which their earthquake support is installed. Accordingly, Snider, Jr. et al. have no motivation to provide a series of prefabricated modular concrete forms for casting pier caps in situ, as is provided by the present invention.
U.S. Pat. No. 5,966,764 issued on Oct. 19, 1999 to Dennis A. Vodicka, titled xe2x80x9cRoll Beam Girder System For Bridges,xe2x80x9d describes a longitudinal girder system utilizing mating sections of steel girders formed by means of a conventional rolling process. The girders are built up of two individual girders stacked vertically, with end to end mating sections having a xe2x80x9ckeystonexe2x80x9d fit and forming a slight arch when assembled. The system allows the relatively shorter girder sections to be prefabricated at a manufacturing site remote from the bridge construction for ease of transport, and quickly assembled at the construction site. However, no disclosure is made of any prefabricated pier cap forms for assembly at the construction site, as provided by the present prefabricated pier system invention.
Finally, U.S. Pat. No. 6,141,936 issued on Nov. 7, 2000 to Robert P. Butler, Jr., titled xe2x80x9cprefabricated Concrete Footings,xe2x80x9d describes a prefabricated concrete footing for relatively light construction, such as for use in supporting columns for decks and single story structures. The Butler, Jr. prefabricated concrete footings solve various problems with accurate mixing and preparation of excessive quantities of concrete which may occur at the building site. However, Butler, Jr. does not disclose the construction of any prefabricated modular concrete forms at a manufacturing site, for transport to the site for assembly and forming concrete structures therefrom at the building site, as provided by the present invention.
None of the above inventions and patents, either singly or in combination, is seen to describe the instant invention as claimed.
The present invention is a prefabricated pier system for facilitating and accelerating the construction of bridges, overpasses, and other related structures requiring a series of spaced apart, generally vertical columns for supporting further structure thereupon. The present prefabricated system may be used to support a conventional horizontally disposed girder assembly, or may be used to support a series of prefabricated compression girders constructed in accordance with U.S. Pat. No. 5,966,764 issued to the present inventor, discussed further above and incorporated herein by reference.
The present system comprises a series of prefabricated column or pier base socket or sleeve assemblies and a further series of modular pier cap forms, which are manufactured at a site remote from the construction site of the bridge or other structure. These prefabricated components are then transported to the construction site for the pier supported structure. The pier base sleeve assemblies are secured (preferably welded) to a pair of parallel, underlying leveling beams which are in turn set into the concrete pier foundation. A series of steel HP (xe2x80x9cHxe2x80x9d section pile) members is then placed in the pier base sleeves, and the pier cap forms are assembled in place atop the HP column members, and permanently secured (welded, etc.) thereto.
If conventional horizontal girders are to be used in the structure, the completed pier cap form assembly is filled with concrete (with appropriate reinforcing and girder anchor means), and the horizontal girders are attached. If the compression girders of the present inventor""s issued ""764 U.S. Patent are used, then any required support members (additional H or I beam lengths, etc.) are installed within the pier cap forms, the horizontal longitudinal girders of the structure are installed atop these support members, and the pier cap forms are filled with concrete and appropriate reinforcing means.
It will be seen that the concrete does not provide any addition in strength to the present steel structure, but rather provides additional weight and mass which serves to anchor the underlying pier structure more substantially. The present system thus provides three different anchoring principles for the structure: (1) The pier members are welded (or otherwise securely attached) at their ends to the underlying pier foundation sockets and to the prefabricated pockets of the pier cap sections, respectively; (2) wedge members are installed in the pier end pockets of the pier caps, to the outside of each pier member pair, to wedge the abutting upper ends of the pier members securely within each pier cap pocket; and (3) the weight and mass of the concrete fill within the pier cap form assembly provides additional compressive force on the pier caps to anchor the system together. The present invention thus results in relatively quick and straightforward construction for bridges, overpasses, and other similar structures requiring a series of piers, pier caps, and girders in their construction.
Accordingly, it is a principal object of the invention to provide a prefabricated pier system for the construction of bridges, overpasses, and the like, in which the system comprises a series of prefabricated pier foundation members and pier cap form members fabricated at a site remote from the construction site, with the pier foundation members and pier cap members being transported to the construction site for assembly.
It is another object of the invention to provide pier foundation members, each member comprising two spaced apart sockets for seating the lower ends of a corresponding pair of steel H section pier members therein, and pier cap members, each member comprising a box-like structure having a pier pocket depending therefrom for accepting the upper ends of a pair of pier members therein.
It is a further object of the invention to provide a series of pier cap members of modular construction for end to end assembly at the construction site, with the assembled pier cap form serving as the structural pier cap and further serving as a permanent form for casting concrete therein.
Still another object of the invention is to provide a prefabricated pier system which is adaptable to the support of both conventional rolled steel girders and to girders constructed in accordance the disclosure of U.S. Pat. No. 5,966,764, issued to the present inventor and incorporated herein by reference.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.